A cloud computing service in a broad sense may be regarded as a service delivery and consumption mode.
A cloud service provider (CSP) connects a large quantity of computing resources using a network and performs unified management, allocation and scheduling, and the computing resources constitute a huge computing resource pool to provide services for cloud service consumers (CSC). For the CSCs, cloud resources may be infinitely expanded and have characteristics of high efficiency and flexibility, for example, request on demand and payment per use.
Platform as a service (PaaS) is a common service mode of broad-sense cloud computing. PaaS provides a middleware platform (covering a database, an application server, and the like) for a user as a service, where the middleware platform is developed in a customized manner. Essentially, PaaS converts a resource service of the Internet into a programmable interface, to provide a third-party developer with a resource and service platform that has a commercial value. With support of a PaaS platform, a cloud computing developer obtains a large quantity of programmable elements. These programmable elements have specific service logic, which brings great convenience to development, not only improving development efficiency but also reducing development costs.
In the prior art, a user may deploy an application on a virtual machine managed by a CSP server, and the CSP server (for example, AMAZON EC2) performs duplication to obtain several identical standby virtual machines (with the same application installed and in a ready-to-run state). The CSP server starts a standby virtual machine to undertake the corresponding load together with the currently running virtual machine when load of a running virtual machine reaches a threshold set in a resilient policy. However, in the prior art, standby virtual machine resources are directly requested when an application is deployed, resulting in a low utilization rate of virtual machine resources.